1. Field of the Invention
The present invention relates to imaging stands, and more particularly, to an imaging stand to be used for imaging with a CR cassette or an FPD cassette installed therein.
2. Description of the Related Art
For the purpose of disease diagnoses and the like, radiation images such as X-ray images are widely used. Such radiation images for medical use are conventionally taken with the use of a screen-type film, but CR (Computed Radiography) devices using stimulable phosphor sheets have been developed to digitize radiation images. In recent years, radiographic imaging devices (flat panel detectors) that detect emitted radiation with radiation detecting elements and acquire the detected radiation as digital image data have been developed.
With a CR device, a CR cassette having a stimulable phosphor sheet in a cassette-type housing is conventionally installed in an imaging stand (also called a bucky imaging stand, a detector holder, or the like), and radiographic imaging is then performed in many cases. Radiographic imaging devices used to be developed as special-purpose devices formed integrally with supporting bases (see JP 3890163 B1 and JP 9-73144 A, for example). However, portable radiographic imaging devices that have radiation detecting elements and the like in housings and are designed to be portable have been developed and been put into practical use in recent years (see JP 2006-58124 A and JP 6-342099 A, for example). Such a portable radiographic imaging device will be hereinafter referred to simply as an FPD cassette. CR cassettes and FPD cassettes will be hereinafter collectively referred to as cassette-type detectors.
Meanwhile, various kinds of imaging stands each including a bucky into which a cassette-type detector is to be installed are being developed (see JP 2005-21233 A, for example). In many cases, an imaging stand is designed to be able to accommodate a cassette-type detector of 10×12 inches (quarter), 11×14 inches (large quarter), 14×14 inches (large square), 14×17 inches (half), 17×17 inches, or the like.
In a case where imaging is performed with a cassette-type detector of 14×17 inches installed in an imaging stand, for example, a cassette-type detector D is installed horizontally in an upper portion of the holder 102 in the bucky 101 of an imaging stand 100 as shown in FIG. 16A, or a cassette-type detector D is installed horizontally in a center position in terms of the vertical direction in the holder 102 as shown in FIG. 16B, or a cassette-type detector D is installed vertically in a center position in terms of the horizontal direction in the holder 102 as shown in FIG. 17A, for example.
Hereinafter, a case where a cassette-type detector D is installed horizontally in an upper portion of the holder 102 as shown in FIG. 16A will be referred to as “landscape top”, a case where a cassette-type detector D is installed horizontally in a center position in terms of the vertical direction in the holder 102 as shown in FIG. 16B will be referred to as “landscape center”, and a case where a cassette-type detector D is installed vertically in a center position in terms of the horizontal direction in the holder 102 as shown in FIG. 17A will be referred to as “portrait”.
In a case where imaging is performed with a cassette-type detector D of 17×17 inches installed in an imaging stand, for example, the cassette-type detector D is installed in the holder 102 as shown in FIG. 17B. The position of the upper edge of a cassette-type detector D of 14×17 inches placed in the “landscape top” position (see FIG. 16A), the position of the upper edge of a cassette-type detector D of 14×17 inches placed in the “portrait” position (see FIG. 17A), and the position of the upper edge of a cassette-type detector D of 17×17 inches (see FIG. 17B) are made to be the same (at the same height from the floor surface or the like).
In a case where the orientation and the position of a cassette-type detector (an FPD cassette or a CR cassette) installed in a conventional imaging stand are changed, a complicated operation needs to be performed to pull the installed cassette-type detector D out of the holder 102 of the imaging stand 100, adjust the position of the guide 103 that is to hold the cassette-type detector D when the cassette-type detector D is installed, and insert the cassette-type detector D back into the holder 102.
As a result, not only the operability of the imaging stand 100 is degraded, but also the cassette-type detector D might be dropped when the cassette-type detector D is pulled out of or inserted back into the holder 102 as described above. If the cassette-type detector D is dropped, the cassette-type detector D might be broken, or the operator such as a radiological technologist might be injured as the cassette-type detector D falls onto a foot of the operator or crashes into the body of the operator, for example.
So as to improve such a situation and change the orientation and the like of the cassette-type detector D in the imaging stand 100 while avoiding ejection and insertion of the cassette-type detector D as much as possible, the holder 102 of the imaging stand 100 is provided on the back surface side of the imaging stand 100, and a rotating mechanism that can rotate the holder 102 relative to the supporting member 104 supporting the holder 102 from the back surface side has been developed and is attached to the imaging stand 100. In this structure, when the holder 102 holding a cassette-type detector D is rotated 90 degrees, the orientation and the position of the cassette-type detector D can be readily changed between the “landscape center” position (see FIG. 16B) and the “portrait” position (see FIG. 17A).
However, if the holder 102 is rotated 90 degrees while a cassette-type detector D is in the “landscape top” position (see FIG. 16A), the orientation of the cassette-type detector D is changed to a vertical orientation, but the cassette-type detector D is not placed at the center in terms of the horizontal direction in the holder 102 and is shifted to the right or left, as can be clearly seen when FIG. 16A is rotated 90 degrees clockwise or counterclockwise. Therefore, there is a need to provide not only the mechanism for rotating the holder 102 but also a mechanism for adjusting the position of the cassette-type detector D by moving the cassette-type detector D in the holder 102 or moving the holder 102. With the addition of such a mechanism, not only the operability of the imaging stand 100 is degraded, but also higher costs are required. Furthermore, if the mechanism becomes complicated, high-precision adjustment of the orientation and the position of the cassette-type detector D in the imaging stand 100 might become difficult.